Research & Implementation Of Open VDR Based On Ethernet

Voyage Data Recorder (VDR) is one important device which is used to record various parameters during the ship navigation. These data are very important support to analyze marine disaster reason. Current VDR device adopts built-in industrial control PCB board and various board cards. It has high integration level. But its flexibility is low and not easy to upgrade. Most important, it is not easy for later stage repair and maintenance. Based on this situation, this article has come up with one VDR system based on Ethernet infrastructure. Package image card, sound card, data acquisition card, storage unit and main control unit into modules based Ethernet network interface. It realizes information acquisition, transmission and storage via network. Each module has high level independency. If the communication protocol between interfaces is not changed, one module technology updating will not have impact on other modules. It adopts network interface. During implementation, it can increase or reduce modules based on ship dynamic situation. It has high level flexibility. If there is any fault, we can do single diagnosis for single module. It can orient the fault point very fast. So it does not need to have professional engineer to replace modules.Based on IMO and China relevant VDR standard analysis, we come up with system design scheme. We define each module's function. At the same time, we have made detailed design and implementation for three modules which include navigation data acquisition box, main control box and radar image acquisition box.Concerning navigation data acquisition box design, based on this module characteristics, adopts SOPC technology, imbedded Nios server soft core into FPGA, combined with real time high efficient uC/OA II imbedded system micro-inner core and small TCP/IP protocol stack, it completes system function. Concerning SOPC and development process, it has made detailed discussion. It has investigated acquisition-required navigation data type and characteristics and designed reasonable task and processing flow.Concerning main control box design, it adopts up-to-date ARM technology and combines powerful uClinux operation system to realize wanted functions. It has made detailed discussion of ARM technology. It has made investigation of S3C44BOX peripheral interface circuit, uClinux transplantation on S3C44BOX and MTD device driving under uClinux.Concerning radar image acquisition box design, based on radar image data large amount, high point frequency and low level acquisition frequency, it comes up with the scheme which uses FPGA as acquisition control and use ARM as later stage disposal. It has made detailed analysis on radar image acquisition difficulty. It has made deep investigation of the problem of the synchronization of AD conversion output clock and ARM bus frequency. And it comes up with using 2 asynchronous FIFO realization method.After every module being validated independently, the entire system is tested synthetically.The result indicated that the system function is satified the designed requirements.This article is not only successful to come up with one new infrastructure and functional dvantage VDR system. At the same time, various modules'design technology and method just need to be modified in small part, then they can be applied to other areas. It has powerful versatility.